Dobbies



W. WICKER March 28, 1961 DOBBIES Filed Jan. 24, 1958;

Unite DOBBIES Walter Wicker, Oberrieden, Switzerland, assignor to Gebr.Stiiubli & Co., Horgen, Switzerland, a Swiss company The presentinvention relates to a dobby with a pattern card, at least one drawknife and draw hooks associated with the knife and controlled forengagement with the knife according to the pattern.

In known dobbies of this kind the hooks are supported and carried byso-called hook needles in such manner that during the idle movement ofthe draw knife those hooks which do not have to be engaged by the drawknife during the next pick are lifted off the draw knife by the hookneedles. If an attempt is made to operate dobbies of this kind at highspeed, the lifting of the hooks takes place abruptly so that faultlesscontrol of the hooks may fail to take place. In order to free the hookneedles from such loads, according to the invention all draw hooksengaged by the draw knife are lifted off the knife, for the purpose offurther control of the hooks according to the pattern, by one and thesame member, so that some of the hooks, in accordance with the pattern,need only be supported by supporting members assigned to them.

7 Two embodiments of the invention chosen by way of example areparticularly described hereinafter with reference to the accompanyingdrawings, in which:

Fig. 1 is a section through part of a double-lift openshed dobby, and

Fig. 2 is a similar section through a different doublelift open-sheddobby.

In the first embodiment, levers 2 are rotatably supported on a shaft 1and each lever 2 is connected through a rod 3 to a heald shaft. Baulklevers 4 are pivotally connected to the levers 2 and are at all timesurged towards fixed stops 5 by spring loading acting on the healdshafts. Two knives 6 and 7 are driven exactly oppositely to one anotherin a known manner. In Fig. l the upper knife 6 is in the drawn-outposition, and the hook 8 of One of the two baulk levers 4 shown in thedrawing is engaged with this knife. This position indicates that baulklever 4 has been rocked so that its associated heald shaft has beendrawn into the upper shed. During the preceding control, during whichthe knife 6 was in its basic position, the upper hook 9 was supported bya support needle 10 and therefore could not engage with the knife 6. Thesupport needles 10 are actuated by presser needles 11 and a presser rail12. Support needles 14 are associated with the lower hooks 13.

The lower knife 7 is in the basic position, so that the hooks 13associated with it can be controlled. While the knife 7 is in this basicposition, it first makes a clockwise rotary movement so that the hooks13 are lifted away from the engagement surface of the knife by a singlemeans in the form of a support surface 15 arranged on the knife. Amechanism for rotating the knife is described by way of example in US.Patent No. 2,815,044 and does not form part of the present invention.While the hooks 13 are in this raised position, the support needles 14associated with them are controlled in accordance with the pattern. Whena reading needle 16 associated with a support needle 14 has fallen intoa hole in the pattern card 17, the associated pressure needle 18 is tsPatent 0 2,976,891 Patented Mar. 28, 1961 displaced to the right by thepresser rail 19, so that the associated support needle 14 is pushed awayto the right. The top ends of the support needles 14 are clamped firmlyin a fixed transverse member 20 and tend, owing to their own resiliency,to bear against a transverse member 21. In this position the bent lowerends of the support needles 14 are under projections 22 on the hook 13,so that these hooks cannot engage with the knife 7 when the kniferotates counter-clockwise and ceases to prevent the hooks fromdescending, before it is drawn out. But those hooks 13 having thesupport needles 14 which have been pushed away to the right can engagewith the knife 7 when it is rotated counter-clockwise, so that thesehooks are subsequently drawn out by the knife 7.

The upper support needles it are clamped firmly in the transverse member21 and bear against a transverse member 23 owing to their own resiliencyif they are not pushed away to the right by the presser needles 11 orpushed away to the right by their respective hooks as describedhereinafter.

When the knife 6 together with the hook 8 returns to its basic position,the projection 24 impinges against the top end of the associated supportneedle 10 and pushes this needle to the right; Then, as soon as theknife 6 begins to rotate clockwise in order to lift the hooks engagedwith it off its engagement surface, the needles 10 that have been pushedaway can move back to the left and bear against the transverse member23; in this position the top ,end of the support needle is under theprojection 24, so that the hook 8 is not engaged with the knife 6 whenthe latter is next drawn out. But if the hook is to be engaged with theknife again, the appropriate support needle is pushed away to the rightas described, so that its top end in not under the projection 24 and thehook 8 can engage with the knife 6. Similar processes take place in thecase of the lower hooks 13 and the associated support needles 14. It isclear that the free ends of the support needles 10 and 14 have to bemoved only in the longitudinal direction of the hooks in order tocontrol the hooks in accordance with the pattern.

In the dobby shown in Fig. 2, knives 25 and 26 move to and frooppositely to one another in straight slots in plates 27 and are drivenby a mechanism known per se and not shown in the drawings. While theknife 26 is in the drawn-out position, the knife 25 is making its idlemovement, so. that the hooks 28 can be controlled in accordance with thepattern. At the beginning of the idle movement, all hooks engaged withthe knife 25 are lifted off the knife by a single means in the form of agrid 29 which is shown in its raised position and which serves to guidethe hooks 28. The presser needle 39 assigned to the hook 28, togetherwith a stop 31 secured to said needle, has been pushed to the right bythe presser rail 32, since the appropriate reading needle 33 has falleninto a hole in the pattern card 34. Thus, the projection 35 of the hook28 is not supported and the hook 28 can engage with the knife 25 as soonas the grid 29 is lowered again. The presser needle 36 is not acted onby the presser rail 32, because the appropriate reading needle 33 isstanding on the pattern card 34. Therefore, the stop 37 is under theprojection of another hook which is not visible in the drawing but isadjacent to the hook 28; consequently, when the knife 25 is next drawnout, this other hook is not drawn out. The presser needles are loaded bysprings 33 in such manner that they are always pushed back into theirextreme lefthand position as soon as the presser rail moves back to theleft. When the hook 39 engaged with the lower knife 26 returns to itsbasic position, the projection 40 on the hook impinges against the stop41 on the presser needle 42 and pushes the latter slightly to the right,before the hooks are raised by the grid 43 which, like the grid 29, is asingle means for raising the associated hooks. This lifting takes placewhile the knife 26 is making its idle movement, and causes the presserneedle 42 to be released. When the reading needle 44 associated with thepresser needle 42 has fallen into a hole in the pattern card 34, andwhen the presser needle 42 is pushed to the right by the presser rail45, the book 39 can engage with the knife 26 before the latter is nextdrawn out. In this embodiment also, the stops formed as supportingmembers are movable in the longitudinal direction of the hooks. Theupward and downward movement of the grids 29 and 43 is effected forinstance by means of a cam disc which is not shown in the drawings butis arranged underneath the grids.

What is claimed is:

1. In a dobby comprising a pattern card, at least one draw knife havingan engagement surface, draw hooks associated with said knife andcontrolled for engagement with the knife according to the pattern,supporting members for said .draw hooks, single means for taking all thedraw hooks associated with the knife out of engagement with theengagement surface of the knife, whereby some of the hooks, inaccordance with the pattern, need only be supported by the supportingmembers, respectively, associated with them for the purpose of the nextcontrol of the hooks according to the pattern.

2. A dobby as claimed in claim 1, wherein each book is provided with aprojection which is adapted to cooperate with the associated supportingmember to push said supporting member away resiliently when the hooksare engaged with the knife.

3. A dobby as claimed in claim 1, wherein each hook is provided with aprojection which is adapted to co-operate with the associated supportingmember when the hooks are engaged with the knife to push said supportingmember away resiliently, those pushed-away supporting members which haveto keep their associated hooks in the upper position when the knife isnext drawn out being automatically adapted to return resiliently as soonas the hooks are lifted from the knife engagement surface by said singlemeans to their rest position in which the supporting members engageunder the projections on the hooks.

4. A dobby as claimed in claim 1, wherein each hook is provided wtih aprojection which is adapted to co-operate with the associated supportingmember when the hooks are engaged with the knife to push said supportingmember away restliently, those pushed-away supporting members which haveto keep their associated hooks in the upper position when the knife isnext drawn out being automatically adapted to return resiliently as soonas the hooks are lifted from the knife engagement surface by said singlemeans to their rest position in which the supporting members engageunder the projections on the hooks, each supporting member beingconnected to a longitudinally displaceable presser needle adapted topush the supporting member away from the rest position in accordancewith the pattern in order to cause the engagement of the associated hookwith the knife.

5. A dobby as claimed in claim 1, wherein each hook is provided with aprojection which is adapted to co-opcrate with the associated supportingmember when the hooks are engaged with the knife to push said supportingmember away resiliently, the supporting member being defined by a needleclamped fast at one end, the resilient action being obtained by theelasticity of the needle itself.

6. A dobby as claimed in claim 1, wherein each hook is provided with aprojection which is adapted to co-opcrate with the associated supportingmember when the hooks are engaged with the knife to push said supportingmember away resiliently, those pushed-away supporting members which haveto keep their associated hooks in the upper position when the knife isnext drawn out being automatically adapted to return resiliently as soonas the hooks are lifted from the knife engagement surface by said singlemeans to their rest position in which the supporting members engageunder the projections on the hooks, the supporting member being definedby a needle clamped fast atone end, the resilient action being obtainedby the elasticity of the needle itself.

7. A dobby as claimed in claim 1, wherein each hook is provided with aprojection which is adapted .to. co-operate with the associatedsupporting member when the hooks are engaged with the knife to push saidsupporting member away resiliently, those pushed-away supporting memberswhich have to keep their associated hooks in the upper position when theknife is next drawn out being automatically adapted to returnresiliently as soon as the hooks are lifted from the knife engagementsurface -by said single means to their rest position in which thesupporting members engage under the projections on the hooks, eachsupporting member being connected to a longitudinally displaceablepresser needle adapted to push the supporting member away out of therest position in accordance with the pattern to cause the engagement ofthe associated hook with the knife, the supporting member being definedby a stop screwed to the presser needle.

References Cited in the file of this patent UNITED STATES PATENTS2,815,044 Staubli Dec. 3, 1957 FOREIGN PATENTS 427,774 Great BritainApr. 30, 1935 657,967 Germany Mar. 18, 1938

